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You are welcome. It is a pretty useful home remedy, and I was also startled that something so effective isn't more known. (Although it may be one of those things that Greatgrandpa and Greatgrandma knew all about, and just didn't talk about in public.) I gather that normal-strength mint teas help against them forming, too.

PS. I think I found out why you and another commenter have not been able to post comments. It looks like the anti-spam system marked both of you as spam, and I was finally able to find some comments that got marked that way and unmark them. I hope the same thing hasn't been happening to other people. (And I don't know why I couldn't find them before in my anti-spam pile. Wordpress is weird.)

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As a native-born Pittsburgher, which has a number of public stairways of similar vertigiousness, I have to ask - where are the handrails? You lose your balance on that sucker, it's a long way down without anything to grab other than bits of masonry.